diff --git a/addons/web/static/src/js/fields/basic_fields.js b/addons/web/static/src/js/fields/basic_fields.js
index 4c5bef2c366..f5f59235a0c 100644
--- a/addons/web/static/src/js/fields/basic_fields.js
+++ b/addons/web/static/src/js/fields/basic_fields.js
@@ -705,6 +705,11 @@ var FieldDateRange = InputField.extend({
                 self.$el.data('daterangepicker').hide();
             }
         });
+
+        // Prevent bootstrap from focusing on modal (which breaks hours drop-down in firefox)
+        this.$pickerContainer.on('focusin.bs.modal', 'select', function (ev) {
+            ev.stopPropagation();
+        });
     },
 });